Fatty acids as chemotaxonomic and ecophysiological traits in green microalgae (desmids, Zygnematophyceae, Streptophyta): A discriminant analysis approach. (February 2020)

• Record Type: Journal Article
• Authors: Stamenković, Marija; Steinwall, Elin; Nilsson, Anders K.; Wulff, Angela
• Is Part Of: Phytochemistry. Volume 170(2020)
• Publication Date: 2020-02
• Subjects: Zygnematophyceae -- Desmids -- Chemotaxonomy -- Biomarker -- Ecophysiological trait -- Stearidonic acid -- Discriminant analysis; FA fatty acid -- LA linoleic acid -- ALA α-linolenic acid -- GLA γ-linolenic acid -- SDA stearidonic acid -- ARA arachidonic acid -- EPA eicosapentaenoic acid -- DHA docosahexaenoic acid -- SFA saturated fatty acid -- MUFA monounsaturated fatty acid -- PUFA polyunsaturated fatty acid -- LDA linear discriminant analysis -- MGDG monogalactosyldiacylglycerol -- DGDG digalactosyldiacylglycerol -- TAG triacylglycerol; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2019.112200
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Desmids (Zygnematophyceae) are a group of poorly studied green microalgae. The aim of the present study was to identify fatty acids (FAs) that could be used as biomarkers in desmids in general, and to determine FAs as traits within different ecophysiological desmid groups. FA profiles of 29 desmid strains were determined and analysed with respect to their geographic origin, trophic preference and age of cultivation. It appeared that merely FAs present in relatively large proportions such as palmitic, linoleic, α-linolenic and hexadecatrienoic acids could be used as biomarkers for reliable categorization of this microalgal group. Linear discriminant analysis applied to three a priori defined groups of desmids, revealed clear strain-specific characteristics regarding FA distribution, influenced by climate and trophic conditions at the source sites as well as by the age of culture and growth phase. Accordingly, when considering FAs for the determination of lower taxonomic ranks we recommend using the term "trait" instead of "biomarker", as the latter designates unchangeable "fingerprint" of a specific taxon. Furthermore, despite that desmids were regarded as microalgae having stable genomes, long-term cultivation appeared to cause modifications in FA metabolic pathways, evident as a larger proportion of stearidonic acid in desmid strains cultivated over extensive time periods (>35 years). Graphical abstract: Climate had the highest impact on fatty acid composition in 29 desmid strains investigated, and discriminant analysis significantly separated four clusters of strains according to their geographic origin. Image 1 Highlights: Climate at the source site had the highest impact on desmid fatty acid profiles. Stearidonic acid accumulated in desmids cultivated continuously over 35 years. Fatty acids as markers are proposed to define higher ranks in microalgal taxonomy.